Actual production cost of one single bicoin is aroundt $530-$550. Any price below $500 is a steal. Buy now or regret years later. With difficulty ever increasing miners are getting screwed now cause anyone mining now is running at a loss.
How do you come up with these numbers ? If i assume that an industrial mining operator with access to really cheap electricity(0.05c/kw) has a current miner running, it is still profitable even with a bitcoin price of 55$.
You can check my math: Antminer s3 440gh equals 0.008068 btc per day. The price of the units electricity for a whole day is 0.44 cent. (0.366 kw per hour)
0.008068 * 55$ - electricity = 0.443 - 0.439
Of course this is an extreme example, there are more expanses. For example the price of the miner. But if you already have a miner, that means that you paid for it in advance. You would let it run until btc goes below 55$. (insane thought lol)